Prosecutors began presenting their case Tuesday against Joseph Naso, a 78-year-old photographer charged with killing four Marin County women with matching initials in the 1970s and 1990s.

The preliminary hearing against Naso, who was representing himself in what could be a death penalty case, marked the first time Marin County prosecutors publicly detailed their case.

Some details have emerged since Naso was arrested in April following a routine search of his Reno, Nev., home for a probation violation.

Investigators found that Naso kept a numbered list of 10 women including the four prostitutes he is charged with killing, and kept news clippings of the slayings in a safety deposit box, according to a probable cause statement released last year.

So far, prosecutors have not said if they had identified the six other women mentioned on Naso's list. Investigators have said he is also being investigated for possible links to New York's "Double Initial Murders" of three girls, each with matching initials, in the early 1970s.

District Attorney Ed Berberian did not return a message seeking comment. At the hearing, prosecutors presented evidence to a judge who would decide if they have enough to send Naso to trial.

Naso was charged with killing Roxene Roggasch, Carmen Colon, Pamela Parsons and Tracy Tafoya between 1977 and 1994. He has pleaded not guilty.

A probable cause statement said Naso might have used his then-wife's panty hose to strangle Roggasch, a prostitute whose 1977 murder went unsolved for decades. Authorities say the DNA of Naso's ex-wife was found on the hose.

Roggasch's body was found near Lagunitas, a small town near the coast in Marin County.

Colon's decomposed body was found in 1978 by a California Highway Patrol officer in Contra Costa County. Authorities have said DNA evidence collected from her fingernails could tie Naso to her slaying.

Parsons' strangled body was found in Yuba City in 1993, where Naso was living at the time with his mentally ill son. Court documents state that Naso had photographed Parsons.

Tafoya was also a Yuba City woman killed when Naso lived there. Her body was found on the side of Highway 70 near Marysville Cemetery in 1994.